Vibratory compactor

ABSTRACT

A vibratory compactor for compacting unhardened concrete, and the like, comprises an electrically operated vibration-generating unit having a first mount and a hand-grip unit having a second mount. A rod-shaped vibration-damping connector connects the units and has first and second end portions respectively joined with the first and second mounts. An electric cable supplies energy to the vibration-generating unit, and a switch arrangement selectively permits and interrupts the flow of energy through the cable. The switch arrangement comprises an actuator member mounted on the handgrip unit. The actuator member is movable to a first position permitting the flow of energy, and is permanently biased to a second position interrupting the flow of energy. The possibility of damage to the vibration-generating unit resulting from inadvertent extended operation of the same is prevented, and the compactor may be conveniently employed as a handtool.

United States Patent Strohbeck Jan. 1, 1974 VIBRATORY COMPACTOR Primary Examiner-Robert W. Jenkins [75] Inventor: Gotthilf Strohbeck, Leonberg, Att0rney-M1chael Smker Germany [73] Assignee: Robert Bosch GmbH, Stuttgart, [57] ABSTRACT Germ y A vibratory compactor for compacting unhardened [22] Filed Mar 23 1972 concrete, and the like, comprises an electrically oper- Appl. No.: 237,444

ated vibration-generating unit having a first mount and a hand-grip unit having a second mount. A rod-shaped vibration-damping connector connects the units and has first and second end portions respectively joined with the first and second mounts. An electric cable supplies energy to the vibration-generating unit, and a switch arrangement selectively permits and interrupts the flow of energy through the cable. The switch arrangement comprises an actuator member mounted on the handgrip unit. The actuator member is movable to a first position permitting the flow of energy, and is permanently biased to a second position interrupting the flow of energy. The possibility of damage to the vibration-generating unit resulting from inadvertent extended operation of the same is prevented, and the compactor may be conveniently employed as a handtool.

13 Claims, 3 Drawing Figures VIBRATORY COMPACTOR BACKGROUND OF THE INVENTION The present invention relates to vibration-generating units, and more particularly to vibratory compactors of the type used for compacting unhardened concrete.

Vibratory compactors are of course already known. However, the constructional types heretofore available are characterized by various practical disadvantages which make them awkward to operate, and by other shortcomings which tend to reduce the useful life of the compactor.

A typical prior-art construction makes use of a vibration-generating unit separated from the point of operator control by an elongated tube of fabric-reinforced rubber. Such tubing is provided for purposes of vibration-damping and isolates the operator of the compactor from the severe jolting and jarring which the compactor generates. Typically, such tubing is provided in a length of for instance about feet, and is adequately resistant to the bending stresses to which it is subjected during operation of the unit. At the same time, however, the length of tubing employed makes handling of the compactor awkward and inconvenient, and can make the compactor as a whole rather bulky.

Prior-art compactors of the type under discussion are usually provided at that end of the tubing which is located near the operator with some type of switch arrangement. Specifically, it has been the general practice to provide such compactors with a rotary switch which is turned and set to on and off positions, or to another selected position.

Such arrangements are most disadvantageous in that they can lead to severe damage of the vibrationgenerating unit. As is usually the case, the vibrationgenerating unit comprises an electrical motor driving an unbalanced load. Inasmuch as the vibrationgenerating unit is usually during its operation completely submerged in unhardened concrete or the like, the heat generated; by the motor often cannot be exhausted by means of a simple fan ventilator. However, inasmuch as the unhardened concrete being treated has a considerable heat-absorption capability, it is customary simply to permit the heat generated by the driving motor to be carried off by the surrounding concrete.

The switching arrangement of the prior-art is disadvantageous because it frequently happens that, when a vibration-generating unit is pulled out from a body of unhardened concrete, the drive motor is not immediately shut off. The heat generated by the motor conductors cannot be dissipated, and may build up to such an extent that the motor is actually damaged. In fact, it often happens that, after the vibration-generating unit is withdrawn from the unhardened-concrete, the drive motor will inadvertently be permitted to run for an extended period of time, resulting in complete destruction of the motor. The drive motor is not only the most important, but usually the most expensive part of the compactor, and accordingly quite intolerable.

SUMMARY OF THE INVENTION It is therefore a general object of the invention to remedy the above-described shortcomings of prior-art vibratory compactors.

It is a more particular object to provide a vibratory compactor which is easy to handle.

It is an additional object to provide a vibratory compactor which is not bulky.

It is a further object to provide a compactor which is configurated as a handtool.

It is another object to provide a compactor the vibration-generating unit of which is easily disconnected, allowing for substitution of a unit having different operating characteristics.

Still another object is to provide a compactor in which the driving motor of the vibration-generating unit is protected from damage due to overheating.

It is a further object to provide a compactor having a switch arrangement which can protect the driving motor from damage due to overheating.

It is also an object to provide a compactor with means preventing inadvertent operation of the driving motor when the compactor is not actually in use.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and it method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partially sectioned side view of a vibratory compactor according to the invention;

FIG. 2 is an axial section through the compactor of FIG. 1, taken on line IIII of FIG. 1; and

FIG. 3 is a sectional detail view of a connector for use in the compactor according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a compactor according to the invention. It will be appreciated that this compactor, in marked contrast to prior-art compactors, is provided in the form of a hand-held tool. The vibration-generating unit proper is generally identified by reference numeral 1 and comprises a non-illustrated motor driving an unbalanced load. In conventional manner, vibrationgenerating unit 1 during use of the compactor will be submerged into a body of unhardened concrete, to vibrate such concrete and cause it to settle.

The compactor of FIG. 1 further includes a handgrip unit generally designated by numeral 8. An electrical supply cable 17. enters hand grip unit 8 through a hollow cable guard portion 12, and may be connected to a portable generator provided at a construction site, or to another source of electrical energy.

It will be seen that vibration-generating unit 1 is pro vided with first mounting means, here in the form of projecting portion 13. Likewise, handgrip unit 8 is provided with second mounting means in the form of a projecting portion 6. The units 1 and 8 are linked by rod-shaped connecting means 5, in this embodiment comprising a hollow pipe of somewhat flexible rubber, or another suitable vibration-damping material. It has been found particularly advantageous to provide the connecting means in the form of a pipe of fabricreinforced rubber, but this is merely one possibility.

Vibration-damping connector 5 has a first end portion 21 and a second end portion 22 which are respectively joined with first mounting projection 13 and second mounting projection 6. In the exemplary embodiment of FIG. 1, each of mounting means 6 and 13 comprises a cylindrical first portion and a widened second portion having the configuration of a truncated cone. Furthermore, hollow connector 5 has an internal surface provided with recesses in which the widened portions just described are received and retained. Clearly, the actual joining of connector 5 to units 1 and 8 is accomplished simply by slipping an end of the connector over the respective projecting portion of the mounting means. To ensure a very tight connection, it may be desirable to further employ hose clamping rings 3, 7, which positively clamp the end portions of the connector to the respective projecting portions of units 1 and 8.

With further regard to the illustrated embodiment, it will be seen that second mounting means 6 associated with handgrip unit 8 differs somewhat from first mounting means 13 associated with vibration-generating unit 1. Specifically, mounting means 6 comprises a flange portion 9 connected with the projecting portion of the mounting means. In the illustrated embodiment, the handgrip unit 8 includes a support structure whose support face 10 is illustrated in FIG. 2 and is provided with holes 14 for screws. Advantageously, but merely by way of example, flange portion 9 is screwed to support face 10. Advantageously, a rubber element 16, shown in section in FIG. 3, grips and covers the periphery of flange 9 and the end 22 of tubular connector 5. Element 16 serves to prevent loosening due to vibration. It hardly need be explained that provision of flange 9 and the specific manner of connection depicted are by no means absolutely necessary.

Referring to FIG. 2 it will be seen that supporting face 10 of handgrip unit 8 is provided with a recessed portion constituting socket means, adapted to receive a (non-illustrated) electrical plug associated with the electrical circuit of vibration generating unit 1. The provision of such socket means greatly increases the versatility of the compactor according to the invention, it being possible in a simple manner to exchange one vibration-generating unit 1 for another having different operating characteristics, according to the requirements of a particular application. With the illustrated embodiment, for example, it is necessary merely to remove a hose clamping ring, disengage a mounting means from a respective connector end 22, and remove from socket 15 the electrical plug associated with the circuit of the vibration-generating unit. It is thus a particular advantage of FIGS. 1-3 that an exchange of vibration-generating units can be performed with a screwdriver alone.

FIG. 1 depicts three electrical conductors 2 passing from vibration-generating unit 1 through hollow connector 5 to the non-illustrated plug accomodated in socket 15 of handgrip unit 8. Butt joint connections 4 are provided to take up any tensile forces acting upon the conductors 2, although this is not absolutely necessary, and usually the conductors 2 will be provided as a single cable.

Schematically illustrated switch means SM comprises an actuator member 11 provided on the exterior of handgrip unit 8. Actuator member 11 is movable to a first position in which it permits the flow of energy to the vibration-generating unit, and is permanently bi ased to second position in which it interrups the flow of energy, and thereby interrups operation of the compactor. With such design, the driving motor of the vibration-generating unit cannot operate, unless the actuator 11 is positively held in its first position. In this way, it becomes quite impossible for a worker to inadvertently leave a particular motor running and, if removed from the body of concrete being treated, overheating, because running of the motor ceases immediately upon release of the actuator member.

From the foregoing description, it will be clear that the vibratory compactor according to the invention is used in a manner quite different from that of prior-art constructions. The vibration-generating unit 1 is not dragged around at the end of a long hose-like connector which must be whipped about for purposes of manipulation. Instead, and as depicted in the exemplary embodiment, the invention contemplates the possibility of providing a vibratory compactor in the form of a hand-held tool. Such construction greatly facilitates handling and use. In addition, and as explained before, the switch arrangement by means of which operation of the compactor is controlled eliminates the possibility of overheating as a result of extended inadvertent use.

In the illustrated embodiment, the connector 5 is shown as being made of rubber, and it has already been stated that a connector made of fabric-reinforced rubber has been found particularly advantageous. It is emphasized, however, that other materials may be employed, and that indeed a connector according to the invention can have a form quite different from that shown in FIG. 1. In addition, it has been found advantageous to employ a connector like that illustrated having a length of between about 60 and 120 cm, and preferably about cm. However, such dimensional ranges may be exceeded, if the vibratory compactor continues to have the character of a hand-held tool. Also, whereas the connector 5 of FIG. 1 is made entirely of vibration-damping material, it is of course possible to provide a connector which is made of such material in only a few parts, if the connector nevertheless serves to isolate the user of the compactor from the jarring and jolting produced by the vibration-generating unit.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in vibratory compactors for use in treating unhardened concrete and the like, it is not intended. to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analyses, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Vibratory compactor for compacting unhardened concrete and the like, comprising an electrically operated vibration-generating unit provided with first mounting means; a handgrip unit provided with second mounting means; elongated vibration-damping connecting means connecting said units and having first and second end portions respectively joined with said first and second mounting means; electric cable means for supplying energy to said vibration-generating unit; and switch means for selectively permitting and interrupting the flow of energy through said cable means, and comprising an actuator member mounted on said handgrip unit, said actuator member being movable to a first position permitting the flow of energy and being permanently biased to a second position interrupting the flow of energy, thereby preventing damage to said vibration-generating unit resulting from unintended operation of the same, said handgrip unit being provided with electrical socket means electrically connected with said cable means, and adapted to receive an electrical plug associated with the electrical circuit of said vibration-generating unit, and said connecting means comprising a tube having a hollow interior, said socket means being accessible through the interior of said-tube, whereby the electrical wires associated with said plug and leading from said vibration-generating unit to said socket means may be accommodated within said tube.

2. Vibratory compactor for compacting unhardened concrete and the like, comprising an electrically operated vibration-generating unit provided with first mounting means; a handgrip unit provided with second mounting means; elongated vibration-damping connecting means connecting said units and having first and second end portions respectively joined with said first and second mounting means, said elongated vibration-damping connecting means being sufficiently stiff as to permit pushing of said vibration-generating unit into a body of unhardened concrete by force exerted on said handgrip unit without buckling of said elongated connecting means; electrical cable means for supplying energy to said vibration-generating unit; and switch means for selectively permitting and interrupting the flow of energy through said cable means, and comprising an actuator member mounted on said handgrip unit, said actuator member being movable to a first position permitting the flow of energy and being permanently biased to a second position interrupting the flow of energy, thereby preventing damage to said vibration-generating unit resulting from unintended operation of the same.

3. A vibratory compactor as defined in claim 2, at

leastone of said end portions of said connecting means comprising a tubular end portion, and the respective mounting means comprising a projecting portion received within said tubular end portion.

4. A vibratory compactor as defined in claim 2, said connecting means comprising an elongated tube.

5. A vibratory compactor as defined in claim 2, said connecting means comprising a hollow tube having spaced open ends, at least one of said ends constituting one of said end portions, and said mounting means comprising a projecting portion received within said one of said ends.

6. A vibratory compactor as defined in claim 5, said connecting means further comprising hose clamp means clamping said one of said end portions to said projecting portion.

7. A vibratory compactor as defined in claim 5, said projecting portion having at least one widened part and said tube having an internal surface provided 'with at least one recess in which said widened part is received and retained.

8. A vibratory compactor as defined in claim 2, said handgrip unit being provided with electrical socket means electrically connected with said cable means, and adapted to receive an electrical plug associated with the electrical circuit of said vibration-generating unit.

9. A vibratory compactor as defined in claim 2, said handgrip unit comprising a supporting portion, said connecting means comprising a tube having an open end constituting said second end portion, and said second mounting means comprising a projecting portion received within said open end and a flange connected with said projecting portion and screwed to said supporting portion.

10. A vibratory compactor as defined in claim 2, said connecting means comprising a rubber tube.

11. A vibratory compactor as defined in claim 2, said connecting means comprising a tubular pipe formed of fabric-reinforced rubber.

12. A vibratory compactor as defined in claim 2, one of said end portions being disconnectable from the respective one of said mounting means, whereby to facilitate replacement of one vibration-generating unit by another having different operating characteristics.

13. A vibratory compactor as defined in claim 2, said compactor having the form of a handtool. 

1. Vibratory compactor for compacting unhardened concrete and the like, comprising an electrically operated vibrationgenerating unit provided with first mounting means; a handgrip unit provided with second mounting means; elongated vibrationdamping connecting means connecting said units and having first and second end portions respectively joined with said first and second mounting means; electric cable means for supplying energy to said vibration-generating unit; and switch means for selectively permitting and interrupting the flow of energy through said cable means, and comprising an actuator member mounted on said handgrip unit, said actuator member being movable to a first position permitting the flow of energy and being permanently biased to a second position interrupting the flow of energy, thereby preventing damage to said vibration-generating unit resulting from unintended operation of the same, said handgrip unit being provided with electrical socket means electrically connected with said cable means, and adapted to receive an electrical plug associated with the electrical circuit of said vibration-generating unit, and said connecting means comprising a tube having a hollow interior, said socket means being accessible Through the interior of said tube, whereby the electrical wires associated with said plug and leading from said vibration-generating unit to said socket means may be accommodated within said tube.
 2. Vibratory compactor for compacting unhardened concrete and the like, comprising an electrically operated vibration-generating unit provided with first mounting means; a handgrip unit provided with second mounting means; elongated vibration-damping connecting means connecting said units and having first and second end portions respectively joined with said first and second mounting means, said elongated vibration-damping connecting means being sufficiently stiff as to permit pushing of said vibration-generating unit into a body of unhardened concrete by force exerted on said handgrip unit without buckling of said elongated connecting means; electrical cable means for supplying energy to said vibration-generating unit; and switch means for selectively permitting and interrupting the flow of energy through said cable means, and comprising an actuator member mounted on said hand-grip unit, said actuator member being movable to a first position permitting the flow of energy and being permanently biased to a second position interrupting the flow of energy, thereby preventing damage to said vibration-generating unit resulting from unintended operation of the same.
 3. A vibratory compactor as defined in claim 2, at least one of said end portions of said connecting means comprising a tubular end portion, and the respective mounting means comprising a projecting portion received within said tubular end portion.
 4. A vibratory compactor as defined in claim 2, said connecting means comprising an elongated tube.
 5. A vibratory compactor as defined in claim 2, said connecting means comprising a hollow tube having spaced open ends, at least one of said ends constituting one of said end portions, and said mounting means comprising a projecting portion received within said one of said ends.
 6. A vibratory compactor as defined in claim 5, said connecting means further comprising hose clamp means clamping said one of said end portions to said projecting portion.
 7. A vibratory compactor as defined in claim 5, said projecting portion having at least one widened part and said tube having an internal surface provided with at least one recess in which said widened part is received and retained.
 8. A vibratory compactor as defined in claim 2, said handgrip unit being provided with electrical socket means electrically connected with said cable means, and adapted to receive an electrical plug associated with the electrical circuit of said vibration-generating unit.
 9. A vibratory compactor as defined in claim 2, said handgrip unit comprising a supporting portion, said connecting means comprising a tube having an open end constituting said second end portion, and said second mounting means comprising a projecting portion received within said open end and a flange connected with said projecting portion and screwed to said supporting portion.
 10. A vibratory compactor as defined in claim 2, said connecting means comprising a rubber tube.
 11. A vibratory compactor as defined in claim 2, said connecting means comprising a tubular pipe formed of fabric-reinforced rubber.
 12. A vibratory compactor as defined in claim 2, one of said end portions being disconnectable from the respective one of said mounting means, whereby to facilitate replacement of one vibration-generating unit by another having different operating characteristics.
 13. A vibratory compactor as defined in claim 2, said compactor having the form of a handtool. 